Rotary-hearth furnace



Nov. 25, 1930. A. D. DAUCH ROTARY HEARTH FURNACE Filed March 20, 1926 2 Sheets-Shee'c WITNESSES MMM afm La 0M INVENTOR Nov. 25, 1930. A. D. DAU@ 1,782,956

ROTARY HEARTH FURNACEv Filed March 20, 1926 Z'Sheets-Sheet 2 WITNESSES ZVENTGR /@M f mf@ l WQ/,MM

Patented Nev. 25, .11930 Aran "iai Darien orfrirrsiznneiigfPnnNsYLvANIA,Assieivonjro eine"aan` J; Haelen,"

coiviriiiw,or:rrrrrsnunenjPENNSYLVANIA, A conronarion,oFfrENNsYLvANIA fMy iiiventionlrelates tofindustrial heating A furnaces, more particularlyy to apparatus foi" 1 ROTARYHEA'RTH FURNAGE Applicaties linea, nalga mises.; serai in i.'96,192.9`

`man,ipulatingY the Worlji-. or articleslfto" be is among the 1Vof my invention to t `fprovide an improved typeof industrial heat# v ing furnace which shall;l "embody nie'ans for mechanically discharging the Work or artif cles, that have beenheated, from the furnace chamber, i

l vide mechanicaloperating means for industrial heating? furnaces which shall greatly f `facilitat-ethe hzoindling oftheheated articles,

in dischargingithe same so as to maintain the operating temperature 4 of vthief furnace, Vand Where the :heated yarticles aretobe hardened,

to keep them atsuitable quenching heatsv ,n lnotwher` object` .of my invention is to pro` vide linechaiiicaloperating means of the above designated character fvvvhich'` lshall` be i t `adapted for 'discharging AWorliffrom vfuriiaces t inta mannertofmelfectv its proper distribution; forsubjecting it toa quenchingrbath.

Industrial heating furnaces of he` embodying amovable hearth, as for example o rotary hearth furnaces, are providedffvvith y passagesor openings for loadingthe articles to be heated onV the furnace hearth, or in suitable trays orA removable supports which are `placed on the hearth member and for unload` `ing thevvorkor' Work-carrying members by lifting or Ireirioving the trays orV supports from the' hearth through the discharge `open- Vings.' The charging passages aiieat the cold side i of` the furnace chamber and the fdisf charge'passage orfxpassages at Mthe hot end of prevent as much as possible a drop inthe temperature ofthe heated articles when they are to be subjected to a quenching operatioii.` i It has been the customary l practice to charge thelfurnace byplacingthe articles to `be heated in suitable trays Which are insertedthrough charging passages into *the furnace chamber and placed upon the movable hearth.` The trays vveresubsequently remo-,vedby one o `the hearth and Withdravvingthem through the discharge passage. 'u i accordance vvithmy presentinventionl employfa `plurality of Work-carrying trays Which `karesecurely fixedtothehearthso'as to or' niorewoperatbrs manuallygliftingthem be o permanent` part thereof, the traysfbeing n mounted in Suchamanner that" they may be Y readily removedfor renewal or repairs,` The traysbeing iXedto the hearthl arenotreto they arey cooled by a cold charge of material Whereas by themethod of removing thetrays Afrom the furnacechainber the tray inadditionl to its chargehadtobeheated y quiredto. be heated oth-er`than to the extent to the operating temperature of the furnace,

furnace. *y

,I furthe? rvide" mede,anicel` @Pertg mechanism Ifor discharging the contents of thus, `met erialijg `irieraising niet load the 4the trays at the discharge passage of the fur-` nace to eliminate theextensive manipulation ofthe Work by operatorsfvvhich left the `dist time to e'ecta material drop inthe tempera-4 ture ofthe furnace. A `I furthenprovide means cooperating with the mechanical discharging apparatus for operating the cover member or closure of thedischargedpassagetol open the i passage when the mechanism f Vfunctions to `chargepassage openlforsuificient lengths of l .unloadthe charge ffroinrthe traysandto automatically ,close the sanieyvhenfthedischarge mechanism assun'iesits" inoperative" position; In the' accompanying drawings constitiit` ing a part hereofV in `Whichdilre reference vievv partially in fs'e'ction "fand partially in elevation of a rotary lnea'rt-h furnace embody,-`

'ing the principlesofmyinvention; and

2 is a cross-sectional view thereof illustrating the relativepositionf of the Work-carrying trays which are supported on thehearth.`

eferring to Figfl of the drawings, the

structure therein illustrated comprises a pedestal` support 1 `provided with -a clamping ring 2 `to which is secured a bearing support rotatable support 7 havingja centralhub n portion 8 provided with a depending flange 9 is mounted on the bearing member 6, the flanges 5 and 9 of the bearing support and rotating member 7 cooperating to enclose the bearing member 6. A vertical spindle or drive shaft 10 is secured to the rotatable support 7` to adapt the latter to rotate therewith and is journaled in the center column 11 of the furnace member and provided with a suitable drive connection comprising a pair of bevel gears 12 and 13. The gear 13 is mounted on a shaft 14 carrying a worm wheel contained in the gear case 15, the worm wheel interacting with 4a worm `shaft 16 connected by the coupling 17 to drive motor 18, adapted for intermittent rotation.

A hearth 20 is secured to the rotatable support 7 by suitable angle bars 21 and a plurality of segment-'shaped trays 22 having pedestal supports 23 are hinged at 24 to mounting brackets anchored in the hearth portion 20. The trays 22 are closed at their inner ends and open at the ends extending to the outer extremity of the hearth.

The furnace wall 25 is constructed of suitable refractory and heat-insulating material and a roof 26 of similar material forms a chamber 27 with the outer walls 25 and the center column 11.

The furnace wall 25 is provided with openings or passages 30 and 31 for respectively charging and discharging the articles to be heated into and from the segment shaped trays 22 of the hearth. The passages 30 and 31 are separated by a partition wall not shown which extends from the outer wall 25 to the center column 11 of the furnace for the purpose of preventing a cooling of the furnace chamber in the region of the discharge passage 31 which is the hot Zone of the furnace. Suitable heating elements 32 and 33 are disposed around the inner and outer walls of the wall portion 25 and center column 11, respectively, these elements being energized from a suitable source of electrical energy.

The discharge passage 31 is provided with a chute 35, the upper extremity of which is in Valignment with the tray members 22 and a door 36 is connected to angle bars 37 secured to the sides ofthe passage 35. to prevent the infiltration of cold air into the heating chamber. The door 36 is provided Vwith a bracket 38 which is connected by a cable 39 ext-ending over a pulley 40 to a lever 41.

The trays 22 are adapted to be raised above their hinged supports 24 to discharge their contents into the chute 35 by means of a gripping member or hook 43, that is secured to a movable ram 44 and adapted to extend underneath the trays 22 to engage thelatter when the ram 44 is actuated. The ram is disposed for longitudinal movement in a metal housing 45 which extends through the roof 26 of the furnace and is fastened to the structural frame work 46 carrying the driving mechanism previously described.

A vertical extension 47 is connected to the cross-member 46 and a bearing bracket 48 is mounted on the cross member to rotatably journal a screw mechanism comprising a screw shaftV 49 having a bevel gear 50 secured at its lower extremity which is in cooperative engagement with a gear wheel '51 mounted on the shaft ofva motor 5 2. T he eX- tended end of the screw shaft 49 is similarly journale'd in an angle bracket 53 secured to the top or crest of the vertical extension 47. A guide rod 54 is clamped at its respective ends to the brackets 48 and 53 and a nut member having a threaded opening interacting with the threads of the screw shaft 49 is provided with an opening for receiving the guide rod 54 to guide the nut55 in its axial movement along the screw shaft 49 to the position indicated by the dotted lines. The nut member 55 connects to the ram 44 which extends through an opening provided in the bracket 48 and through the casing 45.

In operation, the discharging mechanism comprising the hook 43 and the screw actuated ram functions to lift the trays in the manner shown in the dotted line construction against the roof of the furnace which is provided with a stop block 57 with which the trays are engaged with a certain amount of impact to cause the articles carried by the tray to be loosened and passed into the chute 35. When the gripping member or hook 43 assumes the position in which the tray 22 is fully tilted the nut member 55 will have traversed the tripping lever 41whieh extends directly in its path and by engaging the same the door 36 is raised on its hinge to open the passage through which the material is discharged into a quenching bath or onto a suitable conveyor.

The segment shape of the tray members 22 effects a spreading or scattering of the articles carried on the tray at the instant they are discharged therefrom, which is desirable to properly distribute the material before submitting it to the quenching fluid and to enhance this spreading of the articles the tray may be provided with a flared bottom or otherwise shaped to carry-out this function.

Then the contents of the tray havebeen discharged through the chute 35 the motor 52 is operated in a reversedirection of rotation to cause the gripping member 43 to assume its normal or lowered position as shown in Fig. 17 and the door 36 will close by gravity when the trip lever 41 is released. It is evident that by the utilization of hinged trays which are permanently mounted on the hearth of the furnace and the mechanical tilting mechanism the articles or work may be readily discharged through the discharge passage 31 in a minimum of time and without manual labor and that the tray-tilting mechanism will be adapted, tof-function ,in "its tiltn" operation for each successive tray as it is rought in alignment with the discharge passage by intermittent rotation ofthe rotatable support on which the hearth is mounted. f'

' d vn .risvobviousfthat astray-liftinglmchai i `nism'magy'f be disposed underneath thehearth and arranged to function in pushing the Ytray l upward about its hingedsupport or that the tray may be hinged at itsv other end'fand discharge its contents to a chute adapted to convey it from the center offthe furnace.

. `struction and in the design and arrangement Although I have vdescribed one of the emf bodiments of my invention, it Will be obvious` to those skilled'in the art thatvarious'modifications vmay be made in the details ofconi i of the several cooperating parts Without deuni) `parting from the `principles herein set forth.

Iclaim:V Y y 1.`In Van industrial heating furnace the combination with a movable hearth of a plurality `of Work 'carryingA members supported` thereon, said furnace fbeing provided with passages communicating with the `furnace chamber, and means-independent of the -movement of said hearth for actuating said carrying members to discharge the Worlr through one of said passages.

2. In an industrial heating furnace the combinationwith a movable hearth of'a plurality of Work carrying members supported thereon,`said furnace being provided Withpassages communicating With the furnace chamber, and actuating means independent of the vmovement of the hearth for tilting said carrying members to discharge the` Work through one of said passages. y

3. In an industrial heating furnace the combination With a movable hearth of a' plurality of Work carrying members supported i discharge the Work through oneV of said pas-V i' sages WhenV the movement of said hearth is interrupted.

thereon, said furnace being` provided With passages communicating with the furnace chamber, adrive mechanism for impartino' intermittent movementto said hearth, and` means for actuating said'carryingmembers to `41:. ln an industrial heating furnace the i combination with a movable hearth of a plurality of Work carrying `members supported thereon,` said furnace being provided With i closed passages communicating with the furnace chamber, means for actuating said carn rying members to i discharge the` Work through one of said passages, and means associated With said actuating meansA for opening said discharge passage.

5. In an industrial heating furnace thecoinbination With amovable hearth of a plurality of Work carrying members supported thereon, said furnace being provided With closed passages communicating with the furnace chamber, means independent of the movement ofthe hearth for actuating said i carrying members` tori. discharge Y the -i `Work the Worktherethrough.y` L l 6, VIn l industrial heating through one of-saidpassages, and means for .3

automatically opening said discharge pas- Q] Vsageisimultaneouslyl.with the Adischargingof l7a i.

fanart@ combinationlwitha rotatable hearth of apluy rality of work?Carryngvmemberssur Qrbd "thereon, ..Sadifurnee 1 being Previde with Y passages communicating with the fliilee chamber, and actuating` `means inde endent I operative alignment therewith` VWheiisaid iwork carrying members are col combination a rotatable hearth of a plu: rality `of jWork carrying members-supported l "thereon, said," furnace beingf provided .With i passages` `communicating `with. theifurnace .Chambers e drive mechanism 1 for repartie intermittent rotative .movement `l to sai hearth 2 and` means forL dischargingfthe work .from said-carrying member through onezof 1.

7 -Inj an industrial heating "furnace i the said .passages when the movement" of hearth isl interrupted;` 1

,i 8.111 anindustrial i `combination.With a rotatablehearthof apllil y i i i i ralityof segment shapeditrays for carrying articles to be heated securedby hinges.. at their large end to the outer portionlof saidhearth 'and means for moving said trays angularly about Ltheir-hinge supports todischarge their contenta M 9. An industrialA hatirig' @the lprising a i furnace, chamber, rotatable supiportjournaled for rotation about a,,vertifcal` axisinsaid chamber, an annular hearth car` ried said support, a plurality fof segment means for actuating said support to provide Vintermittent rotative.` `movement l. to :said

all@

hearth and trays, and `means for raising said j trays.,l nitheirfhinge supports to` discharge prisinga furnacev chamber, af rotatable sup4- port journaled for rotation about arvertical axisin said chamber, anannularfhearthVcar- 'said trays on their hinge supports to discharge their contents, said lastnamed means s comprising `a grippingmember adapted for` i lengagementtvith the undersideof said trays, `and ai motor actuated screw` and nut mecha- -nism for'raisingsaidgrippingmember. ttgl ato() shaped trays pivotallyconnected at one of` Atheii` ends tosaid hearth,means for providing uniform heat circulation around said trays,

Lelli.) i

11. A furnace provided with a discharge opening, a movable hearth Within the furnace, material carrying pans upon said hearth, means for moving the hearth through the furnace, means for stopping the hearth as each pan registers with the discharge opening and means for dumping each pan as it registers with the discharge opening.

12.` A furnace provided With a discharge opening, a rotary hearth within the furnace, material carrying pans upon said hearth, means for rotating the hearth Within the furnace, means for stopping the hearth as each pan registers with the discharge opening and means for dumping each pan as it registers with the discharge opening.

13. A furnace provided With a charging opening and a discharge opening, a movable heart-h Within the furnace, material carrying pans upon said hearth, means for moving the hearth, means for stopping the hearth as one pan registers with the charging opening and another pan registers With the discharge opening, and means for dumping each pan as it registers with the discharge opening.

14. In an industrial heating furnace the combination with a movable hearth of a plurality of'Work carrying members supported thereon, said furnace being provided With passages communicating With the furnace chamber, and means independent of the movelnentvof the hearth for actuatingsaid carrying members and for freeing the Work from its support to discharge the same through one of said passages.

15. In an industrial heating furnace the combination With a movable hearth of a plurality of Work carrying members supported thereon, said furnace being provided With passages communicating with the furnace chamber, means independent of the movement of said hearth for actuating said carrying members and means for freeing the Worlr from its support to discharge the same through one of said passages.

16. In an industrial heating furnace the combination With a movable hearth of a plurality of Work carrying members supported thereon, said furnace being provided with passages communicating With the furnace chamber, and means independent of the movement of said hearth for successively actuating said carrying members 'to discharge the Work through one of said passages.

17. In an industrial heating furnace the combination with a movable hearth of a plurality of Work carrying members supported thereon, said furnace being provided with passages communicating With the furnace chamber, and means independent of the movement of said hearth and operatively disposed in alinement With one of said passages for successively actuating said carrying mem- ALAN D. DAUCI-I. 

